OOP PHP和实例化类

Question

I am relatively new to OOP approach to PHP, but just wanted something clarified:

if(isset($_POST['insertProduct']) && !empty($_POST['productName'])){
    $newProduct = new product();
    $newProduct->productName = $_POST['productName'];
    $newProduct->servingSize = $_POST['servingSize'];
    $productID = $newProduct->insertProduct();   
}

So the above code is executed when a form is posted to the page to enter a new product into the DB.

$selectProduct = new product();
if($selectProduct->getProducts()){
    foreach($selectProduct->getProducts() as $product){ 
        echo '<option value="' .
            $product['productID'] . '">' . 
            $product['productName'] . '</option>';
    }
}

The above piece is on the same page, and obviously now there are two instances of the product class that exist (assuming the form has been posted to add a new product). Does this show a benefit of the OO approach? As in using two instances to access different methods? Or is it a bad way of doing what I want to do?

Answer 1

I think getProducts should be at least a static method, since it doesn't have nothing to do with the instance of a product. A product class should represent only the single data of a product, therefore generic non-instances methods should be set to static or moved to another class.

I'd suggest you to create a Factory class that will create the product instances for you:

$array = FactoryProducts::getProducts();

But you surely need to move that method outside the product class. For the rest, everything seems fine.